Combine 1 cup sugar and flour in a heavy saucepan; add egg yolks, pineapple, and butter, stirring well. Cook mixture over medium heat, stirring constantly, until mixture thickens and comes to a boil. Remove from heat. Cool slightly. Pour filling into pastry shell.
Beat egg whites (at room temperature) and cream of tartar until foamy. Gradually add 1/4 cup plus 2 tablespoons sugar, one tablespoon at a time, beating until sugar dissolves and stiff peaks form. Spread meringue over pie, spreading to edges to seal. Bake at 350° for 10 minutes or until meringue is lightly browned. Cool completely. Serve at room temperature.